A resource-related research proposal is described which extends the Albany High Voltage Electron Microscope (HVEM) Biotechnological Resource Facility. Its specific aims are (a) To provide the necessary HVEM expertise and assistance to outside scientists who are not necessarily familiar with EM methods, but who have projects on mitosis which could benefit substantially from HVEM, and (b) To solicit collaborative projects, on mitosis/meiosis in eggs, from individuals who are working with organisms whose oocytes are known to undergo unusual cell divisions. Both of these collaborative approaches provide an opportunity to answer important long-standing mitotic questions which, because of technical difficulties, have been avoided by conventional ultra-thin section electron microscopists. Five collaborative HVEM projects on mitosis/meiosis, which were either initiated by outside researchers (a-c) or solicited from individuals familiar with unusual organisms (d-e), are detailed. These projects include: (a) The structure of the mitotic center in mercaptoethanol treated sea urchin eggs, (b) The mechanism of prometaphase chromosome oscillations, (c) The three-dimensional arrangement of membranes in the spindle, (d) The formation and structure of the unusual meiotic spindle in oocytes of Xenos, and (e) The role chromosomes play in forming and organizing spindle microtubules. Each of these projects will involve the reconstruction or analysis of mitotic components from HVEM micrographs of serial semi-thick (0.25-0.75-Mum) to thick (1.0-Mum) sections. The long term objective of this proposal is to establish a National resource which allows outside researchers to collaborate with the resource staff on mitotic/meiotic studies which are best approached by HVEM. That such a resource is desirable is evident from the facts that (a) Aside from those described above, many other HVEM studies on mitosis have already been submitted to the resource and these request assistance, and (b) Many questions concerning mitosis/meiosis can best be approached by applying HVEM methods to oocytes of organisms which can most often be supplied by researchers unfamiliar with ultrastructural techniques. It is expected that these studies will greatly improve our understanding of how the mitotic apparatus functions, a problem which is central to understanding the etiology of various birth defect syndromes and to the development of new strategies for the therapeutic control of cell proliferation.